Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to life processes.

Chapter 12 The cell goes through stages of Development  Interphase,Prophase, Metaphase,Anaphase, Telophase. In preparation for eukaryotic cell division, the complete genome is duplicated. As a result, each chromosome consists of two sister chromatid. They have identical copies of the DNA Cell division usually happens in two sequential steps; nuclear division (mitosis), and cytoplasm division (cytokinesis). In mitosis the sister chromatids are pulled apart. In cytokinesis, 2 separate daughter cells are formed w/ a single nucleus and a set of chromosomes B. Cell Division

Created by 1st Period Mitosis- Cell division occurs in every part of your body EXCEPT the creation of sperm and eggs. Meiosis- cell division that only occurs in testicles and ovaries, which only have 23 chromosomes each.

EXPLAIN He la cells. Story

Chapter 12 A. Cell Division. Functions in reproduction, growth and repair Cells reproduce to form new organisms. Unicellular organisms like amoeba, yeast and bacteria-reproduce asexually. In multi-cellular organisms, cells divide (mitosis) for growth and development of an organisms, and replace damaged or dead cells. Cell division allows the transfer of genetic material

Chapter 12 Individuals inherit 46 chromosomes, 23 from each parent. C. Human Life Cycle Individuals inherit 46 chromosomes, 23 from each parent. Meiosis in gonads, halves the chromosome number. Sperm cells (23), Ovum(23). Fertilization restores the chromosome number to 46. The Zygote now has 46. Mitosis prod. Genetically identical daughter cells. Chapter 12

Chapter 12 B. Cell division to distribute identical sets of chromosomes The total hereditary information of a cell is called it genome.

Chapter 12 A. Cell Division Eukaryotic chromosomes are supercoils of DNA-protein complexes called chromatin. Each chromosome is a double stranded molecule of DNA. Segment are called genes. Proteins are involved with the expression, replication and repair of the genes. Humans have 46 chromosomes in the somatic cells. Somatic cells are body cells. Humans also have sex cells or gametes, each w/ half the chromosome # 23.

DNA condenses PMAT –prophase, metaphase, anaphase, telophase Prophase

Chapter 12 This period before metaphase is characterized by the nuclear envelope fragmenting, so microtubules can interact w/ the chromosomes. Spindle fibers extend from each pole toward the cells equator. Kinetochore microtubules become attached to the kinetochores, causing the chromosomes to agitate. G. Prometaphase Review

Chapter 12 H. Metaphase During metaphase, centrosomes are positioned at the opposite poles. Chromosomes move and are aligned at the metaphase plate, in the middle.

Chapter 12 I. Anaphase Anaphase begins when paired centromeres of each chromosome move apart. The centromeres uncouple. Sister chromatids split apart into separate chromosomes and move towards opposite poles of the cell. The number of chromosomes has doubled. Kinetochore fibers pulling the chromatids, shorten as chromosome reach the poles.

Chapter 12 J. Telophase & Cytokinesis During telophase, daughter nuclei begin to form at the two poles. The nuclear envelope forms around the chromosomes, from portions of the endomembrane system The nuclei reappear. The chromatin fibers uncoil. At the end, cytokinesis has begun, and two separate daughters cells have formed. A cleavage furrow forms a grove in the cytoplasm with a ring of actin microfilaments. Plant cells undergo cytokinesis with the formation of a cell plate.

Draw and identify

Chapter 12 K. Mitotic Spindles and microtubules. Microtubules are made of 2 proteins, alpha and beta- tubulin. The kinetochore microtubules arrange the chromosomes and place them in the middle of the cell.

The Cell Cycle ** K-2. Cell Cycle Interphase During G1, the cell increases in size During the S phase, chromosomes are replicated DNA synthesis takes place The G2 Phase (Second Gap Phase) organelles and molecules required for cell division are produced

Chapter 12 The kinetochore provide internal cues that signal The M-phase or check point for chromosome interaction. Cell division is influenced by chemical growth factors, or physical factors like crowding or density- dependent inhibition. Cyclin helps control cell growth. L. Regulating the cell cycle

Chapter 12 Cancer cells do not respond normally to the bodies control mechanisms. They divide excessively, invade other tissues and if unchecked, can kill the organism. Cancer cells in culture do not stop growing in response to cell density, or growth factors. Cells normally recognizes damaged cells, then The immune system finds,and destroys transformed cell that convert to cancer cells. If abnormal cells evade destruction, they may proliferate to form a tumor. Tumors that are malignant, grow out of control, they metastasize, break off and spread. Benign cells grow out of control then stop. M. Cancer